Concept & Prototype Testing Quick Guide
A table read for your idea, a dress rehearsal before it ships. Pick a section — worth bookmarking for next time.
Sketch or Prototype?
The table read comes before the dress rehearsal — don't skip ahead.
- You have more than one direction and need to know which is worth building further.
- The idea is still cheap to throw away — you want reactions before you've fallen in love with it.
- You need to know if the concept makes sense at all, before worrying about how it works.
- The concept is settled and now you need to know if people can actually use itPrototypes answer "does this work," not "is this the right idea" — testing one too early wastes fidelity you didn't need yet.
- Building a polished prototype before testing the underlying conceptA beautiful prototype of the wrong idea is still the wrong idea — just a more expensive version of it.
Who to Test With
Casting the right audience matters more than casting a lot of them.
- 5 people who roughly match your audience is plenty at this stage — you're looking for a pattern, not a statistic.
- Colleagues outside the project can work for a first gut-check, as long as you're clear that's what it is.
- By prototype stage, testers should genuinely match your real audienceYou're now testing usability for real users, not just reaction — a mismatched tester's confusion may not mean anything.
- Anyone who already knows what the concept is "supposed" to doPrior knowledge fills in gaps a real first-time user won't have — their success doesn't predict a stranger's.
Running the Session
A grab-and-go bank of task framings — come back to this before every session.
"Walk me through what you think this is, before I explain anything."
"What would you expect to happen if you tapped/clicked here?"
"What's confusing, even a little, about what you're looking at?"
"If a friend asked what this does, what would you tell them?"
"Your goal is to [specific outcome] — show me how you'd try."
"Keep talking out loud, even when it feels obvious what to do."
"What would you do next, and why?"
"Pretend I'm not here — what would you try if you got stuck?"
Reading the Signal
Early reactions are quiet. Here's how to actually hear them.
- Hesitation before acting — even a pause of a second or two is worth a follow-up question.
- Someone re-reading the same part twice without you prompting them to.
- "Oh, I see" said in a tone that doesn't match the words.
- "I like it" with nothing specific attachedPolite enthusiasm is the most common false positive in early testing — always ask "what specifically" before counting it.
- Whether they say they'd use it in the futureStated future intent is famously unreliable — watch what they do with the thing in front of them right now, not what they predict about tomorrow.
What they hesitate on matters more than what they compliment.